Agreed, it was the fact that the 1996 specials made such a perfect conclusion that makes the later specials so disappointing. The later ones were funny (the whole 'Gary Gang' bit in particular), but the storylines had already been tied up so neatly.
In particular, I like the way that the Trotters could prove ownership of the watch links back to the very first episode where Rodders makes an inventory -it makes the ending so satisfying.
I also like the way that they'd had the watch in their posession all along, which means that from an asset point of view, they'd been millionaires for years without realising (very Trotterish), and that every time Del had said "this time next year, we'll be millionaires" he was actually right.